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https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-12 21:44:06 +08:00
[NETFILTER]: Add refcounting and /proc/net/netfilter interface to nfnetlink_queue
Signed-off-by: Harald Welte <laforge@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Harald Welte
David S. Miller
parent
32519f11d3
commit
838ab63649
@ -81,5 +81,6 @@ enum nfqnl_attr_config {
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NFQA_CFG_PARAMS, /* nfqnl_msg_config_params */
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__NFQA_CFG_MAX
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};
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#define NFQA_CFG_MAX (__NFQA_CFG_MAX-1)
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#endif /* _NFNETLINK_QUEUE_H */
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@ -20,6 +20,7 @@
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#include <linux/notifier.h>
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#include <linux/netdevice.h>
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#include <linux/netfilter.h>
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#include <linux/proc_fs.h>
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#include <linux/netfilter_ipv4.h>
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#include <linux/netfilter_ipv6.h>
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#include <linux/netfilter/nfnetlink.h>
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@ -48,6 +49,7 @@ struct nfqnl_queue_entry {
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struct nfqnl_instance {
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struct hlist_node hlist; /* global list of queues */
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atomic_t use;
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int peer_pid;
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unsigned int queue_maxlen;
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@ -105,17 +107,28 @@ __instance_lookup(u_int16_t queue_num)
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}
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static struct nfqnl_instance *
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instance_lookup(u_int16_t queue_num)
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instance_lookup_get(u_int16_t queue_num)
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{
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struct nfqnl_instance *inst;
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read_lock_bh(&instances_lock);
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inst = __instance_lookup(queue_num);
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if (inst)
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atomic_inc(&inst->use);
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read_unlock_bh(&instances_lock);
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return inst;
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}
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static void
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instance_put(struct nfqnl_instance *inst)
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{
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if (inst && atomic_dec_and_test(&inst->use)) {
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QDEBUG("kfree(inst=%p)\n", inst);
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kfree(inst);
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}
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}
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static struct nfqnl_instance *
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instance_create(u_int16_t queue_num, int pid)
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{
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@ -141,6 +154,8 @@ instance_create(u_int16_t queue_num, int pid)
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inst->copy_range = 0xfffff;
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inst->copy_mode = NFQNL_COPY_NONE;
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atomic_set(&inst->id_sequence, 0);
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/* needs to be two, since we _put() after creation */
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atomic_set(&inst->use, 2);
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inst->lock = SPIN_LOCK_UNLOCKED;
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INIT_LIST_HEAD(&inst->queue_list);
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@ -182,8 +197,8 @@ _instance_destroy2(struct nfqnl_instance *inst, int lock)
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/* then flush all pending skbs from the queue */
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nfqnl_flush(inst, NF_DROP);
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/* and finally free the data structure */
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kfree(inst);
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/* and finally put the refcount */
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instance_put(inst);
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module_put(THIS_MODULE);
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}
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@ -471,7 +486,7 @@ nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
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QDEBUG("entered\n");
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queue = instance_lookup(queuenum);
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queue = instance_lookup_get(queuenum);
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if (!queue) {
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QDEBUG("no queue instance matching\n");
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return -EINVAL;
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@ -479,7 +494,8 @@ nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
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if (queue->copy_mode == NFQNL_COPY_NONE) {
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QDEBUG("mode COPY_NONE, aborting\n");
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return -EAGAIN;
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status = -EAGAIN;
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goto err_out_put;
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}
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entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
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@ -487,7 +503,8 @@ nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
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if (net_ratelimit())
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printk(KERN_ERR
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"nf_queue: OOM in nfqnl_enqueue_packet()\n");
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return -ENOMEM;
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status = -ENOMEM;
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goto err_out_put;
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}
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entry->info = info;
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@ -523,6 +540,7 @@ nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
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__enqueue_entry(queue, entry);
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spin_unlock_bh(&queue->lock);
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instance_put(queue);
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return status;
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err_out_free_nskb:
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@ -533,6 +551,8 @@ err_out_unlock:
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err_out_free:
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kfree(entry);
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err_out_put:
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instance_put(queue);
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return status;
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}
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@ -685,6 +705,12 @@ static struct notifier_block nfqnl_rtnl_notifier = {
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.notifier_call = nfqnl_rcv_nl_event,
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};
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static const int nfqa_verdict_min[NFQA_MAX] = {
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[NFQA_VERDICT_HDR-1] = sizeof(struct nfqnl_msg_verdict_hdr),
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[NFQA_MARK-1] = sizeof(u_int32_t),
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[NFQA_PAYLOAD-1] = 0,
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};
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static int
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nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
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struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
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@ -696,26 +722,40 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
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struct nfqnl_instance *queue;
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unsigned int verdict;
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struct nfqnl_queue_entry *entry;
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int err;
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queue = instance_lookup(queue_num);
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if (nfattr_bad_size(nfqa, NFQA_MAX, nfqa_verdict_min)) {
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QDEBUG("bad attribute size\n");
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return -EINVAL;
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}
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queue = instance_lookup_get(queue_num);
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if (!queue)
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return -ENODEV;
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if (queue->peer_pid != NETLINK_CB(skb).pid)
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return -EPERM;
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if (queue->peer_pid != NETLINK_CB(skb).pid) {
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err = -EPERM;
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goto err_out_put;
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}
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if (!nfqa[NFQA_VERDICT_HDR-1])
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return -EINVAL;
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if (!nfqa[NFQA_VERDICT_HDR-1]) {
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err = -EINVAL;
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goto err_out_put;
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}
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vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]);
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verdict = ntohl(vhdr->verdict);
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if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT)
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return -EINVAL;
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if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) {
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err = -EINVAL;
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goto err_out_put;
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}
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entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id));
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if (entry == NULL)
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return -ENOENT;
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if (entry == NULL) {
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err = -ENOENT;
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goto err_out_put;
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}
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if (nfqa[NFQA_PAYLOAD-1]) {
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if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]),
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@ -727,7 +767,12 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb,
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skb->nfmark = ntohl(*(u_int32_t *)NFA_DATA(nfqa[NFQA_MARK-1]));
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issue_verdict(entry, verdict);
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instance_put(queue);
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return 0;
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err_out_put:
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instance_put(queue);
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return err;
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}
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static int
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@ -737,6 +782,11 @@ nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
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return -ENOTSUPP;
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}
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static const int nfqa_cfg_min[NFQA_CFG_MAX] = {
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[NFQA_CFG_CMD-1] = sizeof(struct nfqnl_msg_config_cmd),
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[NFQA_CFG_PARAMS-1] = sizeof(struct nfqnl_msg_config_params),
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};
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static int
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nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp)
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@ -744,10 +794,16 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
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u_int16_t queue_num = ntohs(nfmsg->res_id);
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struct nfqnl_instance *queue;
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int ret = 0;
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QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type));
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queue = instance_lookup(queue_num);
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if (nfattr_bad_size(nfqa, NFQA_CFG_MAX, nfqa_cfg_min)) {
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QDEBUG("bad attribute size\n");
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return -EINVAL;
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}
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queue = instance_lookup_get(queue_num);
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if (nfqa[NFQA_CFG_CMD-1]) {
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struct nfqnl_msg_config_cmd *cmd;
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cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]);
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@ -766,17 +822,19 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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if (!queue)
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return -ENODEV;
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if (queue->peer_pid != NETLINK_CB(skb).pid)
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return -EPERM;
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if (queue->peer_pid != NETLINK_CB(skb).pid) {
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ret = -EPERM;
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goto out_put;
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}
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instance_destroy(queue);
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break;
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case NFQNL_CFG_CMD_PF_BIND:
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QDEBUG("registering queue handler for pf=%u\n",
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ntohs(cmd->pf));
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return nf_register_queue_handler(ntohs(cmd->pf),
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nfqnl_enqueue_packet,
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NULL);
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ret = nf_register_queue_handler(ntohs(cmd->pf),
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nfqnl_enqueue_packet,
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NULL);
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break;
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case NFQNL_CFG_CMD_PF_UNBIND:
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@ -784,20 +842,23 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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ntohs(cmd->pf));
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/* This is a bug and a feature. We can unregister
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* other handlers(!) */
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return nf_unregister_queue_handler(ntohs(cmd->pf));
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ret = nf_unregister_queue_handler(ntohs(cmd->pf));
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break;
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default:
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return -EINVAL;
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ret = -EINVAL;
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break;
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}
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} else {
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if (!queue) {
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QDEBUG("no config command, and no instance ENOENT\n");
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return -ENOENT;
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ret = -ENOENT;
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goto out_put;
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}
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if (queue->peer_pid != NETLINK_CB(skb).pid) {
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QDEBUG("no config command, and wrong pid\n");
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return -EPERM;
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ret = -EPERM;
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goto out_put;
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}
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}
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@ -809,7 +870,9 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
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ntohl(params->copy_range));
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}
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return 0;
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out_put:
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instance_put(queue);
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return ret;
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}
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static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {
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@ -829,14 +892,132 @@ static struct nfnetlink_subsystem nfqnl_subsys = {
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.cb = nfqnl_cb,
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};
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#ifdef CONFIG_PROC_FS
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struct iter_state {
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unsigned int bucket;
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};
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static struct hlist_node *get_first(struct seq_file *seq)
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{
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struct iter_state *st = seq->private;
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if (!st)
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return NULL;
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for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
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if (!hlist_empty(&instance_table[st->bucket]))
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return instance_table[st->bucket].first;
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}
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return NULL;
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}
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static struct hlist_node *get_next(struct seq_file *seq, struct hlist_node *h)
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{
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struct iter_state *st = seq->private;
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h = h->next;
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while (!h) {
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if (++st->bucket >= INSTANCE_BUCKETS)
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return NULL;
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h = instance_table[st->bucket].first;
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}
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return h;
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}
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static struct hlist_node *get_idx(struct seq_file *seq, loff_t pos)
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{
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struct hlist_node *head;
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head = get_first(seq);
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if (head)
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while (pos && (head = get_next(seq, head)))
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pos--;
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return pos ? NULL : head;
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}
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static void *seq_start(struct seq_file *seq, loff_t *pos)
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{
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read_lock_bh(&instances_lock);
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return get_idx(seq, *pos);
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}
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static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
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{
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(*pos)++;
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return get_next(s, v);
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}
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static void seq_stop(struct seq_file *s, void *v)
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{
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read_unlock_bh(&instances_lock);
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}
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static int seq_show(struct seq_file *s, void *v)
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{
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const struct nfqnl_instance *inst = v;
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return seq_printf(s, "%5d %6d %5d %1d %5d %5d %5d %8d %2d\n",
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inst->queue_num,
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inst->peer_pid, inst->queue_total,
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inst->copy_mode, inst->copy_range,
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inst->queue_dropped, inst->queue_user_dropped,
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atomic_read(&inst->id_sequence),
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atomic_read(&inst->use));
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}
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static struct seq_operations nfqnl_seq_ops = {
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.start = seq_start,
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.next = seq_next,
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.stop = seq_stop,
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.show = seq_show,
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};
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static int nfqnl_open(struct inode *inode, struct file *file)
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{
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struct seq_file *seq;
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struct iter_state *is;
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int ret;
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is = kmalloc(sizeof(*is), GFP_KERNEL);
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if (!is)
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return -ENOMEM;
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memset(is, 0, sizeof(*is));
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ret = seq_open(file, &nfqnl_seq_ops);
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if (ret < 0)
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goto out_free;
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seq = file->private_data;
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seq->private = is;
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return ret;
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out_free:
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kfree(is);
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return ret;
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}
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static struct file_operations nfqnl_file_ops = {
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.owner = THIS_MODULE,
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.open = nfqnl_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release_private,
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};
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#endif /* PROC_FS */
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static int
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init_or_cleanup(int init)
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{
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int status = -ENOMEM;
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int i, status = -ENOMEM;
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#ifdef CONFIG_PROC_FS
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struct proc_dir_entry *proc_nfqueue;
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#endif
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if (!init)
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goto cleanup;
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for (i = 0; i < INSTANCE_BUCKETS; i++)
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INIT_HLIST_HEAD(&instance_table[i]);
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netlink_register_notifier(&nfqnl_rtnl_notifier);
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status = nfnetlink_subsys_register(&nfqnl_subsys);
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if (status < 0) {
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@ -844,14 +1025,25 @@ init_or_cleanup(int init)
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goto cleanup_netlink_notifier;
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}
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#ifdef CONFIG_PROC_FS
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proc_nfqueue = create_proc_entry("nfnetlink_queue", 0440,
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proc_net_netfilter);
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if (!proc_nfqueue)
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goto cleanup_subsys;
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proc_nfqueue->proc_fops = &nfqnl_file_ops;
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#endif
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register_netdevice_notifier(&nfqnl_dev_notifier);
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return status;
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cleanup:
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nf_unregister_queue_handlers(nfqnl_enqueue_packet);
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unregister_netdevice_notifier(&nfqnl_dev_notifier);
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#ifdef CONFIG_PROC_FS
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cleanup_subsys:
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#endif
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nfnetlink_subsys_unregister(&nfqnl_subsys);
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cleanup_netlink_notifier:
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netlink_unregister_notifier(&nfqnl_rtnl_notifier);
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return status;
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